1. Technical Field
The apparatus of the present invention relates generally to interseeding of crops. More specifically, it relates to an apparatus and method of interseeding crops utilizing a center-pivot irrigation system for support of the interseeding apparatus. A primary use, although by no means the only one, it to interseed soybeans into growing wheat. For example, alfalfa, cotton, sorghum, wheat or the like may also be interseeded using the apparatus and method of the present invention.
The invention describes an apparatus wherein a plurality of dispensing stations may be positioned and supported along the main water pipe of a center-pivot irrigation system. Each of the dispensing stations would be capable of the broadcast distribution of dry seeds. Such broadcast might be accomplished using centrifugal force or by use of an air assist wherein the seeds could be propelled using air pressure. As used in this specification, the term broadcast will mean distribution over a wide area, regardless of how that broadcast is effected.
As is well understood in the art, the term "interseed" is used to refer to planting one crop while the other is still standing. As mentioned, one primary use of this technique is interseeding soybeans into standing wheat. After the wheat have been harvested, the soybean crop remains to grow to maturity earlier than would be the case if planting was not commenced until after the wheat were harvested. This techniques artificially widens the "cropping season," permitting the technique to be used further north. Additionally, since soybeans are known to be "nitro-genus" crops, they restore some of the nitrogen to the soil which wheat naturally removes. Thus, in addition to economic incentives, interseeding provides substantial environmental benefits.
As mentioned, the interseeding apparatus of the present invention is adapted to be supported on a conventional center-pivot irrigation system. While the interseeder apparatus of the present invention requires the center-pivot system for support and movement across the field, there is no requirement that the water system be operating. Thus, while it is anticipated that the majority of time the water system will be operated when interseeding, it is not required.
2. Description of the Prior Art
The principles involved in interseeding are well known in the art. In fact the enhanced efficiency involved in such a operation has been a goal of farmers for some time. The transition from theory to practice however, has been difficult. Nevertheless several prior art device have been developed in an effort to practice this interseeding technique.
One such prior art device is disclosed in Ostrom, U.S. Pat. Nos. 4,660,775 and 4,729,514 which disclose a seeding means using a center-pivot irrigation system. This system utilizes a seeding system having an auxiliary water line supported on the main water line. In this embodiment, seeds suspended in the water in the auxiliary water pipe are sprayed out sprinklers, positioned at various points along the line. In another embodiment, the seeds are metered directly into the main water line. The principle of operation is the same except that the seeds suspended in the water are sprayed out through the main water sprinklers. Thus, in both embodiments of the Ostrom device, a "wet" distribution of seeds occurs, wherein the seeds are mixed in water prior to being distributed.
Another example of a prior art device is illustrated in Lyle, U.S. Pat. No. 4,949,656. Lyle discloses a seed distribution manifold for mobile span-and-tower irrigation systems. The seeds are suspended in water and travel in a piping system separate from the irrigation piping, to a manifold which is suspended from the overhead span section. Each manifold distributes seed and carrier water to a plurality of drop tubes. A valve is provided within the manifold to permit the manifold and discharge tube to be filled. A furrow is created by the impact of a high pressure water jet from another nozzle traveling just ahead of the seed drop tube. The valve may then be opened and the water and seed discharged into a planting shoe. There is no mention of a broadcast application. Rather, the seeds flow into the furrow through the tube. Thus, the Lyle patent involves planting of the seeds in narrow rows and not the broadcast distribution of seeds.
Consequently, it is a primary objective of the present invention to provide an interseeder apparatus and method for the broadcast distribution of dry seed.
An additional objective is to provide an interseeder apparatus and method which may be used in conjunction with a center-pivot irrigation system, either with or without the watering system operating.
Another objective is to provide an interseeder apparatus and method wherein a plurality of dispensing stations are positioned along the water arm of the center-pivot irrigation system and wherein the dispensing stations are positioned so as to ensure complete coverage of the area for planting.
Another objective is to provide an interseeder apparatus and method wherein the seeds for distribution are conveyed from a central storage container, positioned adjacent the center stand, to each of the distribution positions.
Another objective is to provide an interseeder apparatus and method wherein the means for conveying the seed from the storage hopper to the dispensing stations and between stations can be any of a number of types such as auger or various types of conveyer.
Another objective is to provide an interseeder apparatus and method wherein the seed may be broadcast using a centrifugal force effect.
Another objective is to provide an interseeder apparatus and method wherein the seed may be broadcast using an "air-assist" effect provided by an air nozzle.